13 is an awkward age. Everyone grows and matures differently...and that's an age where a lot of it is done. Where as the average for a 10 year old or 18 year old might mean something.....it probably varies greatly for someone between 12 and 16. If you are asking this for yourself, all I'd say is - don't worry. I was very small at 13, but it changed very fast - and that's true for a lot of guys.

It'd depend on your height and weight, and as 13 year olds are all really different it's hard to say an average which will have much meaning for you.

75% of the body weight should be EASY ... 100% should be doable but strenuous ... 125% is pushing the limit of what is expected ... above that is abnormally strong.

It depends on how strong they are. Mentally as well as physically! Does he drink lot's of milk? Is he athletic or laid back/lazy? There are a lot of different factors.

If you ask what a typical 25 year old male should be lifting, it is impossible to answer because we all come in varying shapes, sizes and of physical abilities. AT 13, this is even more so, teenagers are so varied in their size and shape that it is impossible to state what the average weight one should be lifting. In fact, weightlifting at this age can actually be very harmful, as the body is still growing at a tremendous rate and placing such an additional physical strain on the muscles and bones can be extremely damaging. Plus, the amount a person can lift depends on what exercise you are doing. For example, what I lift when I bench press is completely different to what I lift when I do weighted squats, or seated rows, etc. So, in summary, I'm sorry but it is impossible to give a figure. Firstly it differes between exercises, as different muscles have different strengths. Secondly, there is no real average weight for any age group. What you may have more luck in getting is a percentage of body weight that can be lifted, as this is easier to calculate - the bigger people tend to be, the heavier they are and this correlates well with the amount they can lift. Serious weightlifting really shouldn't be performed by children of 13 as it can be harmful.

a 13 year old shouldnt be lifting weights. weightlifting under the age of 16 can cause your growth hormone to think you've stopped growing and hence u wont reach the height ur suposed to. i learnt the hard way... lol.